diff --git a/block/io.c b/block/io.c
index d5493ba349cdeaf96aafed85e4160157462394d2..9c04086286e396648d05bfdb8fd163b7e3cd846f 100644
--- a/block/io.c
+++ b/block/io.c
@@ -2283,11 +2283,11 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
     int current_gen = bs->write_gen;
 
     /* Wait until any previous flushes are completed */
-    while (bs->flush_started_gen != bs->flushed_gen) {
+    while (bs->active_flush_req != NULL) {
         qemu_co_queue_wait(&bs->flush_queue);
     }
 
-    bs->flush_started_gen = current_gen;
+    bs->active_flush_req = &req;
 
     /* Write back all layers by calling one driver function */
     if (bs->drv->bdrv_co_flush) {
@@ -2357,6 +2357,7 @@ flush_parent:
 out:
     /* Notify any pending flushes that we have completed */
     bs->flushed_gen = current_gen;
+    bs->active_flush_req = NULL;
     qemu_co_queue_restart_all(&bs->flush_queue);
 
     tracked_request_end(&req);
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 47665be81e2392810a3bc8eff79b7747302a663a..1e939de4fe5a3b04b418edb4c108e82c3c93a0f8 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -443,8 +443,8 @@ struct BlockDriverState {
                          note this is a reference count */
 
     CoQueue flush_queue;            /* Serializing flush queue */
+    BdrvTrackedRequest *active_flush_req; /* Flush request in flight */
     unsigned int write_gen;         /* Current data generation */
-    unsigned int flush_started_gen; /* Generation for which flush has started */
     unsigned int flushed_gen;       /* Flushed write generation */
 
     BlockDriver *drv; /* NULL means no media */